Answer:
8.2+/-0.25
= ( 7.95, 8.45) years
the 95% confidence interval (a,b) = (7.95, 8.45) years
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = 8.2 years
Standard deviation r = 1.1 years
Number of samples n = 75
Confidence interval = 95%
z value(at 95% confidence) = 1.96
Substituting the values we have;
8.2+/-1.96(1.1/√75)
8.2+/-1.96(0.127017059221)
8.2+/-0.248953436074
8.2+/-0.25
= ( 7.95, 8.45)
Therefore the 95% confidence interval (a,b) = (7.95, 8.45) years
Answer:
240
Step-by-step explanation:
Answer:
45
Step-by-step explanation:
2x+2x+2x+3x+3x=540(sum of angels in a five sided polygon)
12x=540
x=45
Step-by-step explanation:
answer ; ( x - 2)( x + 7 )
Answer:
C
Step-by-step explanation:
The multiples of 3 are
3, 6, 9, 12, 15, ...........
The terms form an arithmetic sequence with common difference of 3.
The sum to n terms is
= 
[2a₁ + (n - 1)d ]
where a₁ is the first term and d the common difference
Here a₁ = 3 and d = 3, thus
= 
[ (2 × 3) + (139 × 3) ]
= 70(6 + 417) ] = 70 × 423 = 29610 → C
